With 435 hp and 900 Nm of torque, the new Audi SQ7 TDI is the most powerful diesel SUV on the market. It also leads the competition in numerous other technical fields. Its newly developed 4.0 TDI engine features a world first: An electric powered compressor gives the SQ7 TDI outstanding off-the-line performance. Yet it consumes on average 7.4 litres of fuel per 100 kilometres.
“Following the launch of the successful SQ5, we are now also applying the concept of a diesel- engined S model to the Q7 model line. So equipped, the SQ7 TDI with a V8 TDI engine achieves the consumption figures of a six-cylinder. The new technology solution of the electric powered compressor in the SQ7 TDI is a world first in the competitive environment, with which Audi once again underscores its claim Vorsprung durch Technik,” said Dr. Stefan Knirsch, Member of the Board of Management of Audi AG for Technical Development.
The 4.0 TDI has been newly developed from the ground up. It combines best-in-class performance with low consumption and guarantees maximum dynamics. The V8 engine has a displacement of 3,956 cc. The two exhaust-gas turbochargers are activated selectively according to the concept of sequential charging, since exhaust gas only flows through one turbocharger at low and intermediate load. The second turbine is only activated at higher loads. An electric powered compressor (EPC) augments the work of the two turbochargers, particularly in the lower engine speed range, providing for extremely dynamic off-the-line performance.
With 435 hp and 900 Nm of torque between 1000 and 3250 rpm, the SUV sets new benchmarks in the segment. It accelerates from 0 to 100 kmph in 4.8 seconds; top speed is 250 kmph (governed).
Forced induction concept and electrical system: Electric powered compressor (EPC) and 48-volt subsystem
The electric powered compressor is a world first in a production vehicle. This EPC strongly supports the 4.0 TDI engine when starting off and accelerating from low load for pure dynamics with no turbo lag. It is placed in the air path downstream of the intercooler, close to the engine. Because the EPC does not require any exhaust-gas energy to develop boost, it can be used at any time, thus making it the solution for the traditional weaknesses of the classic exhaust-gas turbocharger. With this technology, turbo lag is history. The EPC provides the engine the boost energy needed for the dynamic delivery of power in less than 250 milliseconds. Driven by a compact electric motor, its compressor wheel spins up to 70,000 revolutions per minute. The 4.0 TDI thus develops its immense power with no perceptible lag: It is available immediately upon depressing the accelerator. That is a major plus, particularly when starting off.
The Audi valvelift system (AVS) is also making its debut in a diesel model from Audi. The inlet and exhaust cam shafts each have two cam contours per valve. On the inlet side, one cam contour supports starting off in conjunction with the EPC, while the other optimizes cylinder filling and thus power at high engine speeds. The AVS system on the exhaust side enables activation of the second exhaust-gas turbocharger. The sequential charging system controls the two exhaust-gas turbochargers so that only one turbocharger is used at low engine speeds. The second is activated additionally at higher loads and engine speeds. The customer benefits from very good torque delivery and dynamic response across the entire engine speed range.
The exhaust streams from the two exhaust valves are hermetically separated, with each driving one of the two turbochargers. In the lower engine speed range, one valve per cylinder remains closed, so that the full exhaust stream flows to the active turbocharger. When load and engine speed increase, the AVS opens the second exhaust valves. This directs flow to and activates the second exhaust-gas turbocharger. The engine achieves its maximum output in this biturbo mode. The switching by the AVS enables fast and precise activation of the second exhaust-gas turbine.
Source: Audi AG
Energizer and Assurance Intl Limited have collaborated on a new line of automotive oil that will be sourced, manufactured, and distributed in India to complement the existing STP product portfolio in ...
The Uno Minda D-90 horn has a two-year manufacturing warranty and is competitively priced between Rs 295 and Rs 855. It can be conveniently purchased from a variety of top-tier online and offline reta...
A two-stage side airbag from ZF Lifetec uses the milliseconds before an unavoidable crash to build up valuable distance and better protect the occupants.